A large number of devices are known for the determination of gaseous components, including those wherein the presence of the gaseous component to be identified can be recognized by optical means.
In a group of the gas sensors known heretofore, the part sensitive with respect to the gaseous component is brought directly into contact with the gaseous sample. Such devices generally exhibit a rather brief response time, but a substantial drawback of these devices resides in that the component responsible for the response effect is, within a rather brief period of time, washed out of the sensor or removed from the surface of the sensor.
Furthermore, sensors are known for the determination of gaseous components in gaseous or liquid samples exhibiting a gas-permeable membrane; when performing the analysis, one side of the gas-permeable membrane is brought into contact with the liquid or gaseous sample, and an electrolyte solution is present on the other side of the gas-permeable membrane, this solution either containing itself an indicator for the penetrating gaseous component or being in contact with a sensor containing the indicator for the gaseous component. Such devices have the disadvantage of a long response time and furthermore are relatively unpleasant to handle, on account of the electrolyte content; they show inadequate stability because of evaporation of the solvent ingredients of the electrolyte solution and they are also sensitive with respect to mechanical damage to the membrane.
It is an object of the present invention to develop a device for the identification of gaseous components in gaseous or liquid samples, this device exhibiting a brief response time combined with a long lifetime, and furthermore being of simple construction, and wherein this device is preferably also suitable for the optical determination of the corresponding gaseous component.